This invention relates to an arthroscope for viewing the internal structure or condition of a human or animal joint. Arthroscopes belong to a class of medical instruments, called endoscopes, that enable physicians to examine, or perform surgery on, various organs and interior body cavities.
Arthroscopes utilize a thin, elongated probe for insertion into or near the region or joint to be examined. Light is transmitted to the inserted (distal) end of the probe, to illuminate the region under observation. An image transmission device, using this light, transmits to the observing physician a view of the region.
A light tube or optic fiber bundle is conventionally used to illuminate the region being observed. If an optic fiber bundle is used, an incoherent bundle will suffice. Transmission of an image from the observed region to the observer, however, requires a coherent bundle. The distal end of the instrument is covered by a lens, which focuses images to be viewed on the ends of the optic fibers in the bundle or transmits these images to a glass image transmission rod.
Arthroscopes are usually equipped with irrigation passages for supplying cleaning liquid to the outside distal end of the probe and keeping it clear for viewing. Air is sometimes also supplied through passages in the probe for the same purpose. In addition, surgical tools can be inserted into an interior body region through an arthroscope probe.
Arthroscopic optical systems began with simple devices in which physicians looked straight ahead through an eye piece. These early instruments were hard to use, however, significantly slowing down the examination and making surgery difficult. A thorough inspection of the interior region required the probe to be wiggled while inserted in the body. Today, however, arthroscopic design has progressed to the stage where the image is displayed on a television monitoring screen.
While these modern arthroscopic systems represent great advances in medical instrumentation and technology, they still suffer from some shortcomings. Principal among these is the lack of realistic three-dimensionality in the image produced by the arthroscope.